No Spitfire?

[buffnut453]

Not that I recall, which is precisely the problem with every suggestion, in any thread, for the RAF using an American design as a primary type in any role. There's no way the American Government would let manufacturing jobs go to the UK...and the logistic chain is just too extended for the RAF to want to rely on an American aircraft as a primary type.

 

[MikeMeech]

Not that I recall, which is precisely the problem with every suggestion, in any thread, for the RAF using an American design as a primary type in any role. There's no way the American Government would let manufacturing jobs go to the UK...and the logistic chain is just too extended for the RAF to want to rely on an American aircraft as a primary type.

Hi

To have fighter aircraft instead of the Spitfire for the BoB the USA could not be relied on to supply anything of a performance greater than the Hurricane. The P40 would have been 'too little, too late'. The F4F would have been the same. That leaves P36 or Buffalo which means you might as well build more Hurricanes. In the real world the British were paying hard cash for various US aircraft types and they were also paying hard cash to expand US aircraft factories. For the BoB the USA could not supply fighter aircraft in adequate numbers or performance, licence production would have been a waste of resources especially of Buffalo or P36 types, again Hurricanes would have been an easier task.

Mike

 

[The Basket]

Blackburn : We can make a 350mph fighter!
British Government: Time to buy P-36s!

Any airplane has to be flying in prototype stage in 1936 for this to work. Saying in 1936 that we need a Spitfire is way too late.

Building something under licence is not taking away British jobs especially if it's mated to a British engine. The RAF used plenty American so if the alternative is a P-40 in 1940 I can't see an issue.

But yeah crank out Hurricanes to the max. Sounds like a plan.

 

[pbehn]

A large part of the Spitfires success and a large problem with trying to replace it with anything else that was on the drawing boards was that Mitchell and his team made the inspired guess to use the thin section wing. There was little or no hard data in England at the time to either support this or counter it. Just about everything else the British were designing used much thicker wing sections and the RAE had not yet figured out that there was a severe rise in drag at higher airspeeds (mid 300mph and up) which meant that many British designs ran into a wall and speed estimates were hopelessly optimistic.
Now in a "what if" we can postulate that another design team also selects a thin section wing but then we are dealing with a plane that never even existed on paper at the time.
Any design of the time using a thick section wing and using the Merlin engine of the time is going to be between the Hurricane and Spitfire in performance and probably closer to the Hurricane than the Spitfire.

With regard to the bold AFAK it wasn't just a question of aerodynamics but also one of what makes a good fighter, climb and turn being thought more important, or as important as outright speed, for an interceptor of unescorted bombers climb was obviously important, and since they would obviously be faster than any bomber speed wasnt the top priority, for fighter boys of WW1 who by that time were in senior positions turning and agility were valued, even though speed was always the quest for ww1 fighters too.

 

[GrauGeist]

The P-36, Hurricane and Bf109 were all developed at the same time, they were all accepted into service at roughly the same time.
The early models all had comparable performance profiles and by 1940, were still contemporaries - this was proven in the Battle of France, as was mentioned earlier, where the French Hawk 75 accounted for more victories against the Luftwaffe than any other type in French service.
So I'm wondering how so much would change in the length of time between the Battle if France and the Battle of Britain that would make the Messerschmitt so superior and the Curtiss so helpless.

I know the Curtiss was American made, so it must be a pile of crap from the start, but history shows it was still very capable in the early stage of the war.

And to say that the P-51 was British made is reaching a bit. The BPC told North American what they wanted and NAA designed/built it.

 

[Admiral Beez]

I know the Curtiss was American made, so it must be a pile of crap from the start, but history shows it was still very capable in the early stage of the war. And to say that the P-51 was British made is reaching a bit. The BPC told North American what they wanted and NAA designed/built it.

Stick a Merlin onto the P-36, essentially making an early P-40L, and you're all set.

 

[pbehn]

Stick a Merlin onto the P-36, essentially making an early P-40L, and you're all set.

You don't have to, the P-36 did OK all by itself, what was needed was trained and organised forces. The UK and French air forces, and later the Soviets were beaten on the ground more than in the air, once airfields start to be over run by ground forces you lose our ground crews, spares and supplies and your ability to fight. With a stretch of water to stop a ground advance the Hurricane was perfectly capable of beating the Luftwaffe. It has some advantages, Dowding and Park could change the disposition of fighters overnight, because all airfields have the same machines.

 

[Shortround6]

I'm not sure that there is a point in further discussion about the merits of a thin wing.

Tomo, there was merit to the thin wing. but there were also other requirements besides speed.

Why did Supermarine need a 242, sq ft wing for a 5300lb fighter?
The French MS 405/406 used a 170 sq ft wing for a fighter of roughly the same weight.
The Germans kept the same size wing on the 109 when it changed from the Jumo 210 to the DB 601 engine.

Supermarine actually used smaller wing on the 300 than they did on the 224. In Span, area and thickness.

I would also note that the P-40 used a 15% wing at the root and 9% at the tip which was inherited from the P-36/Hawk 75. While thinner than most British wings it was not as thin as the Spitfire and yet an early P-40 was nearly as fast (at the same altitudes) while substantially heavier. Other things were going on with drag.

BTW the boat analogy doesn't quite work. Yes everybody knew that a thinner boat needed less power for the same speed than a fat boat. However for a useful boat/ship you can't exceed 1.34 times the square root of the waterline length without a sudden and exponential rise in required power due to wave form drag. Bow rises and stern squats. To get around this you either design a planning hull ( still needs a lot of power) or a very, very skinny shallow hull like a rowing racing shell.

Why was Bristol off by 40mph on the estimate for the Beaufighter? They were already flying the Blenheim with essential the same wing ( same airfoil and just about the same size and planform) so they knew EXACTLY how much power they needed to fly at 280mph. What happened at 300mph and up? They didn't have to just look at a foreign aircraft at an airshow and guess. Same for Hawker, When they designed the Typhoon they were already flying the Hurricane, They knew EXACTLY how much power that plane needed to fly at about 315mph. Why were their calculations off by so much for the Typhoon?
The Drag calculations they were using weren't taking something into account at the higher speeds even if they were accurate at lower speeds.

 

[The Basket]

P-51 was a British contract.
Problem is the Frenchies also wanted the P-36 so this is not ideal. Bit of a log jam there.

The Spitfire has no rival or peer in the allied side so you either have to invent one or settle. To my knowledge nothing else in the UK was flying at the time that could rival. Certainly nothing in France or USA.

 

[Admiral Beez]

"The Defiant will never be remembered as a great operational aeroplane, but it deserves to be remembered as an aircraft with almost no flying vices."

The Defiant should also be remembered as the only successful combat aircraft Boulton Paul ever made. It's amazing that an aviation firm could stay in business for almost fifty years whilst producing mediocre aircraft in penny packet quantities. Clearly their place was in the contract manufacturing of other firms' aircraft.

My favourite Boulton Paul aircraft is the Balliol. With its folding wings, hook, tandem seats and dual controls the postwar Sea Balliol would have made for an excellent FAA pilot training aircraft pre-war. It was too late for its moment.

 

[pbehn]

As I understand it the discussion in aerodynamic terms is or was not whether the wing was thick but where it was thick. On planes like the Typhoon the problem wasn't just with the wings it was also around the chin radiator and wing root.

 

[Admiral Beez]

On planes like the Typhoon the problem wasn't just with the wings it was also around the chin radiator and wing root.

Keep the tail on and all else can be forgiven.

 

[pbehn]

Keep the tail on and all else can be forgiven.

I think you need Spitfire shaped wings too, according to Mr Camm.

 

[Shortround6]

Stick a Merlin onto the P-36, essentially making an early P-40L, and you're all set.

Wrong Merlin.
Timing is everything.
In 1936 and early 1937 you would be taking a radial with a rating of 950hp take-off out of the plane and sticking a V-12 with a take-off rating of 880hp in.

The Y1P-36 (3 of them) were ordered in July of 1936 and delivered in March/April of 1937.
See: Curtiss P-36A
Sticking a Merlin III in the Plane might do wonders for the high altitude performance but take-off and low altitude performance could be worse/perhaps a lot worse as the Curtiss planes used that "Satan inspired device" the constant speed, variable pitch propeller. The Y1P-36s got Hamilton Standards. The Production P-36s got Curtiss electric propellers.
The P-36 had no protection and performance figures are for 100 US gallons except for range which is for about 150/160 gallons.
Production P-36s gained about 200lbs over the Y1P-36s.
US P-36 initial production planes were rated on 92 octane fuel at first.
The contract for the P-36 production planes was placed on July 7th 1937 and first production examples were delivered in April/May of 1938.

Now figure out when any proposed test flying would be done (or prototype for the British ordered/delivered) license agreement negotiated, how long it would take to redo ALL production drawings to British standards and line up British subcontractors or purchase American parts (Curtiss did not make their own landing gear, brakes, hydraulic or electrical parts.)

maybe it could be done but it would be a very tight timeline and which version of the P-36/Hawk 75 do the British get?

 

[Shortround6]

Some of what changed between the Battle for France and the Battle of Britain was the altitudes changed.
In the B of F both sides were trying to do a lot of tactical support which meant the bombers were flying at low to medium altitudes. Which meant most of the fighter combats were at low to medium altitudes.
The Germans certainly started the BoB with low altitude raids on radar installations and RAF air fields but a lot of the later raids were more medium to high altitude (high for the time) with both sides trying to stage fighters at 20,000ft to as high as 30,000ft in order to get "the Bounce". A tactic that was not used anywhere near as much in France.

The American engines used in the P-36 had critical altitudes thousands of feet lower than the Merlin.
There was no suitable British substitute except, perhaps, the Pegasus. Now tell Bomber command they aren't going to get as many Hampdens and/or Wellingtons

later versions of the US engines using 100 octane fuel did get somewhat better but they are too late for the first year or two of the war.

 

[PAT303]

The Spitfire has no rival or peer in the allied side so you either have to invent one or settle. To my knowledge nothing else in the UK was flying at the time that could rival. Certainly nothing in France or USA.

About right, nothing else came close to the Spit, without it the BoB would have still been won but with higher losses, what about the rest of the war, the RAF will loose in every theatre if all they have are Hurricanes Typhoons and P40's.

 

[tomo pauk]

...

Why was Bristol off by 40mph on the estimate for the Beaufighter? They were already flying the Blenheim with essential the same wing ( same airfoil and just about the same size and planform) so they knew EXACTLY how much power they needed to fly at 280mph. What happened at 300mph and up? They didn't have to just look at a foreign aircraft at an airshow and guess. Same for Hawker, When they designed the Typhoon they were already flying the Hurricane, They knew EXACTLY how much power that plane needed to fly at about 315mph. Why were their calculations off by so much for the Typhoon?
The Drag calculations they were using weren't taking something into account at the higher speeds even if they were accurate at lower speeds.

Perhaps people at Bristol didn't applied the cube root law in their calculations? At altitude, the 1st Hercules engines installed on Beaufighter were making ~50% more power at altitude than what Blenheim had. I've found this passage by you in the other thread:
However the cube root law calls for about a 46% increase in power to go from 260 to 290mph, let alone 300 mph.

So if the base speed is 286 mph (best case for Blenheim), and drag and size of the new aircraft are left very close to the base aircraft, a Beaufighter that is doing 320+- mph is just following the cube root rule. On the other hand, perhaps marketing dept at Bristol was keen to sell their product, so the 370 mph figure was communicated to the AM, rather than a 320+- mph one?

A trick for a 'Beaufighter' to be a fast aircraft is that Bristol does a new aircraft design, not to warm up a bomber.

About the Typhoon - again it was perhaps the mis-application of the cube root law (not even the Tempest V did 470 mph), combined with compressibility that will start happening earlier with a 19% t-t-c wing than it will be the case with a 13-15& t-t-c.

I think you need Spitfire shaped wings too, according to Mr Camm.

Sir Sidney was perhaps right to blame other people, but a) he was calling the shots in Hawker wrt. fighter design, and b) it was not Supermarine's fault that he gotten the wing thickness wrong twice.

 

[fastmongrel]

Perhaps people at Bristol didn't applied the cube root law in their calculations? At altitude, the 1st Hercules engines installed on Beaufighter were making ~50% more power at altitude than what Blenheim had. I've found this passage by you in the other thread:
However the cube root law calls for about a 46% increase in power to go from 260 to 290mph, let alone 300 mph.

So if the base speed is 286 mph (best case for Blenheim), and drag and size of the new aircraft are left very close to the base aircraft, a Beaufighter that is doing 320+- mph is just following the cube root rule. On the other hand, perhaps marketing dept at Bristol was keen to sell their product, so the 370 mph figure was communicated to the AM, rather than a 320+- mph one?

A trick for a 'Beaufighter' to be a fast aircraft is that Bristol does a new aircraft design, not to warm up a bomber.

About the Typhoon - again it was perhaps the mis-application of the cube root law (not even the Tempest V did 470 mph), combined with compressibility that will start happening earlier with a 19% t-t-c wing than it will be the case with a 13-15& t-t-c.



Sir Sidney was perhaps right to blame other people, but a) he was calling the shots in Hawker wrt. fighter design, and b) it was not Supermarine's fault that he gotten the wing thickness wrong twice.

Sidney Camm only seems to have listened to Sidney Camm. He was told by RAF pilots that his Typhoon car door canopy was no good for combat because of poor rear vision. He had been told the Hurricane wing was not suitable for high speed work.

Sidney Camm was the only person who knew anything and everyone else was a fool.

 

[Admiral Beez]

Sidney Camm only seems to have listened to Sidney Camm.

Which may explain why his postwar aircraft were so often behind the US and Soviet Union. For example, unlike the supersonic pair of F-100 Super Sabre (entered service in 1954, same year as the Hawker Hunter) and MiG-19 (1955), no Hawker production aircraft ever broke the sound barrier. Of course Camm would likely blame the government and Air Ministry for this lack of capability, but his aircraft so often disappointed. His Sea Hawk (introduced in 1953, a year after the MiG-17) for example should have launched as a swept wing from the onset. The Hawker Sea Fury would have been the best carrier fighter of WW2, had it entered service in 1942 or 43 when the Centaurus production began, instead of 47.

Perhaps the design team behind the innovative and successful Harrier, led by Ralph Hooper got past Camm due to the latter's age. Had he lived it would have been something to see what Supermarine's Mitchell came up with postwar. A better Swift and Scimitar for starters.

 

[fastmongrel]

Had he lived it would have been something to see what Supermarine's Mitchell came up with postwar. A better Swift and Scimitar for starters.

He couldn't have done any worse than the jets Supermarine produced.